Crackdown on Terrorism Financing
Ties Hands of Businessman in Sweden

STOCKHOLM -- At the central train station, a clerk pushes a subway pass and a small pile of change toward Abdirisak Aden -- breaking international law as he does so.

The reason: Mr. Aden, a Somali-born former school principal and partner in a money-transfer office, is on the United Nations' list of those subject to economic sanctions. Citizens of all countries that honor the U.N. list are forbidden to conduct financial transactions with Mr. Aden unless the Security Council specifically approves it. No one can hire him, his...